Valve gear



(No Model.) 2 Sheets-Sheet 1.

H. E. DEPP.

VALVE GEAR. No. 278,689. Patented June 5,1883.

N. PETERS. Phulmuho hu. Wahin mn. DJZ.

FIEZEKIAH E. DEPP, OF SEDALIA, MISSOURI.

VALVE-G EAR.

SPECIFICATION forming part of Letters Patent No. 278,689, dated June 5,1883.

Application filed May 2, 1882. Renewed February 12,1833. (No model.) i I.To all whom it may concern Be it known that I, HEZEKIAH E. DEPP, a

" citizen of the United States, residing at Sedalia, in the county oflettis and State of Missouri, have invented a new and useful Improvementin Valve-Gear, of which the following is a specification.

My invention relates to improvements in valve-motions in which a springcontrivance is used for moving the steam or other sliding valve justafter the piston of the steam-cylinder has finished its stroke 5 and thespecial features of my invention are, first, a device in which a singlespiral spring is compressed for ward and backward alternately for thepurpose of operating the slide-valve by its expansion to] lowin eachcompression; second, the means by which the said spiral valve-operatingspring is compressed and allowed to expand in accordance with themovements of the piston-rod.

The objects of my invention are, first, to secure an equal power bothfor the forward and the backward movement of the valve second, to makethe valve-strokes altogether independent of the piston-rod strokes. Iattain these objects by the mechanism illustrated in the accompanyingdrawings, in which- Figure 1 is a plan view of my improved valvemotion.Fig. 2 is an enlarged cross section in the line .70 00 of Fig. 1 Fig. 3is an enlarged cross-section in the line y g of Fig. 1. Fig. 4 is alongitudinal section in the line 2 z of Fig. 1. Fig. 5 is a sectionsimilar to Fig. 4, but showing the spiral spring compressed and in theact of reversing the valve-stroke. Fig. 6 is an elevation of a modifiedconstruction of my valve-motion. Fig. 7 is a plan view of the same,certain portions of it being broken away in order to expose the spiralspring to view; and Fig. 8 is a diagram of the main portions of thevalve-motion, whereby the spiral spring is operated.

Similar letters refer to similar parts through out the several views.

In Figs. 1, 2, and 3, A represents a suitable support on the frame of asteam-engine cylin-' der. On this support A suitable bearings, aa,

are provided, through which the piston-rod B and valve-rod C are passed.

Opposite the valve-rod O abar, D, is suitably fastened to the bearingsa, and upon this bar the pawls of the valve-motion are fastened, as willbe seen.

The piston-rod B is provided with a forked tappet, I), havingplates 1) 1) through which the valve-rod C and bar D pass.

Between the plates 1) b two plates, 0 c, are provided on the valve-rod Gat a suitable distance apart, and between those plates, and over thevalve-rod O and the bar D, a spiral spring, E, is confined, so as tobear against the said plates 0 c, which are loosely fitted upon the, rod0, and held at a proper distance apart by means of pins 0 The plates 0 0extend over the bar D by means of slots 0", (see Fig. 3,) so as to becapable of freely traveling over the said bar, and operating alternatelythe notched inclined end of a double-armed lever, F, pivoted at f to thebar I). The inclined ends f f of the lever F and thenotches ff* of thelever F stand in opposite directions-viz., ff downward and f j upwardandthe lever F is, by means of a spring, f, in the bar D, held in a normalposition, so that the bottoms of the notches f f stand in line with therespective sides of the slots 0" in the plates 0 0. Thus when the plate0 moves over the inclination f the lever F is moved out of its normalposition, as seen in Fig. 5, and as soon as the said plate 0 standsopposite the notch f the spring f moves the lever D into its normalposition and locks the plate 0. by moving the notch f over it. The sameoperation takes place in alternate succession with the other plate 0 andthe parts f 2 f The length of the lever F is less than the distancebetween the plates 1) b when said plates stand in their normal positionagainst the stop-pins c and this difference of length is a littlegreaterthan the extent of the valve-stroke.

The valve-rod O is provided with two projections, 0" 0 which are in formof ratchet teeth and slant inwardly in opposite directions. Theseprojections extend toward the bar D, upon which two spring-pawls, G G,are 5 provided at a distance apart greater than the distance between theratchet-teeth c" c, the difference between the length of these distancesbeing equal to the length of the valve stroke.

These spring-pawls GG are kept in their normal position by means ofsprings g and stops g, and they are disengaged by means of fingers g y"011 the plates 1) b.

The valve-rod G is provided with stoppingpins H H and bumper-springs h72, and by means of these pins the valve-stroke is limited while thesprings receive the shock or concussion.

In Fig. l the tappet b is represented as just having finished itsforward stroke, the plate being locked by the lever-E, and the valverod0 being locked by the ratchet-tooth c" and spring-pawl G. Thereturn-stroke of the piston-rod brings the plate I) in contact with theplate 0, which plate is then pushed toward the plate 1:, and finallyover the inclined endf of the lever E into the slot f, when the spring fcauses the lever I to lock the plate 0. Just before the plate 0 movesover the slotf" the lever E is so moved out of its normal position thatthe plate 0 becomes disengaged from the slot f, and bears against a pin,0 ofthe stilllocked valve-rod (1. This valve-rod 0 becomes disengagedfrom the spring-pawl G by means of the finger g" on the plate If, whichlinger moves against the inclined end g of the pawl G and swings thesame away from the retaining ratchettooth (P immediately after the plate0' has arrived at the pin 6-, and thus sets the valverod free. Thevalverod is thereupon pushed backward by the spring E until its progressis arrested by the spring -h. The same operation is repeated on theother end of the valvemotion on the return-stroke of the piston.

In Figs. 6, 7, and S the piston rod B open ates an oblong frame, I,sliding upon a stationary rod, 17. An expansible or telescope housing,J, incloses the spring E on the valverod 0, and the ends j j of thehousing bear against two collars, j' j, on the valve rod 0, and extendinto the inner open portion of the frame I. A two-armed shaft, K,suitably hung to the main frame A, serves to check alternately theprogress of the' endsj j of the housing J. The arm 7.: of this shaftextends below the housing J, and the arm over the said housing, thedistance between the two arms being less than the distance between thecollars j j. The difference in the distances mentioned is equal to thestroke of the valve, and the stroke of the valve-rod is terminated bythe stopping-pins c c and the bearings of the valve-rod in the frame A.

The frame I is provided with an upper cam, i, opposite the upper arm,7.", and a lower cam, i, opposite the lower arm, 7;. The cams i are solocated with reference to the arms 7; k that only one will operate atthe same time upon an arm.

The piston-rod B is connected with the frame I by means of a lever, I),suitably pivoted at b to a portion of the frame A, and as the frame I isthus moved forward and backward the housing J is alternately compressedfrom one or the other side, and held by either the arm k or 70, as thecase may be. While the compression of the housing is taking place at oneendsayjthe other end, j is held by the arm It, and kept from moving inthe direction of 70 the endj; but as the end j approaches thetermination of its stroke the cam i by means of its inclined lowersurface, depresses the arm 7; until the arm k is thereby moved out ofrange of the end j The endj, thus liberated,

is moved by the spring E away from the end j, and as soon as the strokeof the valve is finished the arm k is depressed sufficiently to descendbehind the end j, and thus prevent it from moving backward with the backstroke of the frame I.

The operation for the back stroke'is similar to that of the forwardstroke, and does not require special description.

\Vhat I claim as my invention, and desire to secure by Letters Patent,ise 1. I11 combination with a valve and a piston movement, the singlespring E, provided with means for alternately effecting the compressionand expansion of the same during each 0 full stroke of the piston,substantially as and for the purpose described.

2. The combination of the rods B and 0, bar D, spring E, plates 0 c,tappet b, fingers g, ratchet-teeth c" c", and spring-pawls G G, sub- 5stantially as and for the purpose described.

3. The combination of the springf, notched lever E, and plates 0 c,substantially as and for the purpose described. f

4. The tappet I), provided with the fingers 'g g", in combination withthe spring E and means by which the single spring is brought intoaction, substantially as and for the purpose described.

5. The rod (1, provided with the ratchet-teeth I05 projections c 0", incombination with the spring-pawls G G, spring E and means by which thesingle spring is brought into action, substantially as and for thepurpose described.

6. The lever F, with bevelsff", and notches. I I0 or slots f f, incombination with the spring E and means whereby the single spring isbrought into action, substantially as and for the purpose described.

7. The combination of the piston-rod B, rod I I 5 0, spring E, andbumper springs II H, substantially as and for the purpose described.

8. The forked tappet b for operating the plates 0 c, and therebycompressing the spring E in opposite directions, substantially as andI20 for the purpose described.

S. M. ,TRUMBULL, I J. RITCHEY.

